Field of the Invention
The invention relates to a drive device for a washing machine having a laundry drum mounted through an at least approximately horizontally disposed shaft within a bearing sleeve of a rigid star carrier attached to a bottom wall of a tub, the drive device being capable of being mounted on a rear side of the tub and including a flat or pancake motor having a stator carrying part with exciting windings and a rotor with magnetizable poles, for directly driving the laundry drum with the drive device.
Such a drive device is known from German Published, Non-Prosecuted Patent Application DE 39 27 426 A1. In that device, the stator carrying part has an insulating part, on which the exciting windings are mounted. The insulating part is annular and is pushed onto the bearing sleeve of the star carrier. A bell-shaped rotor engages around that assembly unit and is fastened, through the use of a screw cap, to a shaft journal of the laundry drum, with the shaft journal projecting rearward beyond the bearing sleeve. Therefore, the stator carrying part, together with the exciting windings, first has to be pushed, preassembled, onto the bearing sleeve in order to assemble the motor. The rotor bell subsequently has to be placed onto the shaft journal and screwed in place. In that case, however, it is certainly impossible to ensure that the internal tolerances (mainly the positioning of the exciting windings in relation to the magnetizable rotor poles) are adhered to, to the extent necessary for the motor to operate properly. This is because time and equipment for adhering to those tolerances are not available in the assembly factory for washing machines.